Kaitlin H. Wade, Ph.D., from the University of Bristol in the United Kingdom, and colleagues estimated the causal effect of BMI on gross-level and detailed cardiovascular health in healthy participants from the Avon Longitudinal Study of Parents and Children at age 17 years (1,420 to 3,108 participants for different outcomes) and an independent sample from the same cohort (for Recall-by-Genotype [RbG]) at age 21 years (386 to 418 participants).

The researchers found that results of both Mendelian randomization (MR) and RbG methodologies suggested that higher BMI causes higher blood pressure and left ventricular mass index in young adults (e.g., difference in left ventricular mass index per 1 kg/m² using MR: 1.07 g/m2.7; P = 3.8710−06 and per 3.58 kg/m² using RbG: 1.65 g/m2.7; P = 0.0001). RbG results suggested a causal role of higher BMI on higher stroke volume and cardiac output but not systemic vascular resistance or total arterial compliance. No causal role of higher BMI on heart rate was seen.

“These consistent results support efforts to reduce BMI from a young age to prevent later adverse cardiovascular health,” the authors write.